The word toxin describes something that can cause harm to the body. Toxins can be environmental in nature, or exogenous, meaning they from the outside the body.

Your adrenals make cortisol in a circadian rhythm; more production in the morning, tapering off through the day. Cortisol is the hormone that provides that "get up and go" in the morning. Cortisol and melatonin work together to support our sleep wake cycle.